1. Field of the Invention
This invention relates to a sheet sorter. More particularly, to a sheet sorter in which printed or typed sheets are fed one by one from a printing or copying machine successively to a plurality of bin trays through a sheet feed passage which is suitably synchronized with the bin trays.
2. Description of the Related Art
A conventional sheet sorter known in the prior art includes a plurality of bin trays situated adjacent to an outlet of a sheet feed passage for supplying printed or copied sheets one by one. The bin trays are stacked in a pile with gaps between adjacent bin trays, and the sheets are fed one by one, to successive bin trays.
To align the outlet of the sheet feed passage successively with the gap between the adjacent bin trays, two solutions have been proposed, i.e., one in which the sheet feed passage is fixed, while the respective bin trays are shifted up and down, successively, as disclosed in, for instance, U.S. Pat. No. 4,512,565, and another in which the sheet feed passage is shiftable up and down, and the bin trays are fixed.
Recently, however, a sheet sorter was proposed in which both the sheet feed passage and the stacked bin trays are shiftable in synchronization with each other, as disclosed in, for instance, U.S. Pat. No. 4,478,406. To attain the mutual movement of both the sheet feed passage and the bin trays, the sheet sorter disclosed in U.S. Pat. No. 4,512,565 employs a pair of cylindrical cams having helical grooves. Each of bin trays has a pair of training pins projected from respective sides of the bin tray at an inlet end thereof in such a manner that the respective pairs of training pins are successively engaged with the helical grooves of the cylindrical cams, to shift the bin trays up or down, and the cylindrical cams are guided vertically to simultaneously shift the sheet feed passage.
However, in this sheet sorter, the mechanism for shifting both the sheet feed passage and bin trays up and down is complicated, since the cylindrical cam must be vertically guided as well as driven via a vertical shaft. In addition, in this sheet sorter the sheet feed passage has no opening mechanism to enable the clearing of a possible sheet jamming.
To remove a sheet jammed in the sheet feed passage, a sheet sorter disclosed in the above mentioned U.S. Pat. No. 4,512,565 is provided with means for turning the bin trays in the horizontal direction, making it possible to move the inlet of the bin tray away from the sheet feed passage. In this sheet sorter, however, although it is advantageous in that a possible sheet jamming can be cleared by a simple operation, a relatively wide machine accommodation space is required for horizontally turning the bin trays.